Lancet Laboratories: Invoice requested multiple times:(

I have requested they send me an invoice many, many times, they just seem not to be able to do this? The claim will expire but they just cannot attach it to an email and send it to me, are people even computer literate in the accounts department at Lancet? Very quick to send an sms, but how on earth do I access this supposed outstanding invoice? I'm also finding the app not user friendly at all